Evaluation of Rigid Versus Nonrigid Fixation Following Orthognathic Surgery The purpose of this study is to determine the preferred method of fixation to avoid relapse following maxillary and mandibular osteotomy to correct facial developmental deformities. Correlations will be established, between rigid and nonrigid fixation techniques, and the degree of relapse as determined by radiographic, cephalometric and clinical assessment. Any changes in the height of the gingiva or the width of the attached gingiva will be recorded. Post-operative changes in facial contours and occlusion will be recorded. Pre- and postoperative speech and swallowing will be assessed. Clinical Study of Oral Endosseous Titanium Implants in Edentulous Subjects The endosseous implant system consists of titanium root analogues with a threaded surface designed to be surgically embedded in the anterior third of the mandible. The root analogues are covered with a mucoperiosteal flap and the surgical site closed and allowed to heal. After healing, the root analogues are uncovered and a coronal segment attached to each root analogue. A complete denture is constructed to restore the mandibular dentition. Cephalometric radiographs, the Cornell medical Index, the Minnesota Multiphasic Personality Inventory, the Denture Satisfaction Questionnaire, a body focus questionnaire, a three day diet record and a rating of foods with respect to difficulty of chewing will be used to obtain data. The information obtained will be utilized to determine if implant supported mandibular dentures significantly effect loss of vertical dimension of occlusion, satisfaction with dentures, food choices and nutrition, perception of difficulty of chewing selected foods, and body focus, when compared to treatment with conventional dentures.